Electric furnace.



Patented Aug. I4, I900.

W. S. HQFIRY. ELECTRIC FURNACE.

(Application filed Aug. 15, 1899.)

(No Model.)

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No. 655,780. Patented Au I4, I900. w. s. HOBBY.

ELECTRIC FURNACE.

(Application filed Aug. 15, 1899.)

2 Sheets-Sheet 2 Terr Fries...

\VILLIAM SMITII nonun on NEYV YORK, N. Y., ASSIGNOR TO THE UNION 1CARBIDE COMPANY, OF CHICAGO, ILLINOIS.

ELECTRIC FURNACE.

SPECIFICATION forming part of Letters Patent No 655,780, dated August14, 1900. Application filed August 15,1899. Serial No. 727,279. (Nomodeh] T0 aZZ whom it may concern.- ferred character and which may berun con- Be it known that I,WILLIAM SMITH IIORRY, tinuously in onedirection or may be reciproa subject of Her Majesty the Queen ofEngeating, powertransmission mechanism for land, and a resident of thecity of New York, independently connecting the regulating ele- 55 5 inthe State of New York, have invented cerment of each furnace-with themotor appatain new and useful Improvements in Elecratus to shift it ineither direction and for tric Furnaces, of which the following is adisconnecting the same, electromechanical specification. controllingdevices in operative position to The present invention constitutes animthe furnace-circuit and adapted to automatic- 6o 10 provement upon theinvention described and ally actuate the power-transmissionmechanclaimed in my pending application, Serial ism only when thevariations of the furnace- No. 706,352, filed February 21, 1899; and itscircuit amperage exceeds certain predeterprincipal object is to providefor the automined limits, and thereby keep the amperes matic regulationof many furnaces by means approximately constant in the furnace, and 15of a single motor apparatus and without the a switch constructed andarranged to control expense and complication which arise when thepower-transmission mechanism by hand, a separate motor is employed foreach furto shift the regulating element in either dinace. The apparatusdescribed in said aprection, and to permit and prevent control plicationcomprises an electric furnace, the by the electromechanical devices. 2omovable member or element of which is op- The nature, characteristicfeatures, and

eratively connected with the motor, which is scope of my invention willbe more fully unstarted, stopped, or reversed in such manderstoodfromthefollowingdescription,taken ner and at such times as to keep the aminconnection with the accompanying drawperes constant in the furnace andwhich ings, forming part hereof, and in which 25 is controlled byelectromechanical devices Figure 1 is a view illustrating a plant workedby the f urnace-current itself. In that equipped with apparatusembodying features application there is contemplated the use of myinvention and showing at the left hand of a motor for each furnace, sothat there a motor apparatus which operates to shift will be as manymotors as furnaces, and the regulating elements of the furnaces shown oconsequently there will be required many in the center of the figure andat the rightsmall motors and much undesirable complihand side, upon anenlarged scale, portions cation. All motors when started continue of theregulating elements. Fig. 2 is a diato run on by reason of the inertiaof their grammatic view showing features of the in parts, even aftertheir driving power hasbeen vention, and Fig. 3 is a detail viewillustrat- 35 interrupted, and this defect is disadvantaingpower-transmission mechanism adapted geous, because the motors tend torun on and for use in connection with my invention. in that way lower orraise the furnace-am- Referring to the drawings, a motor 1, which peresafter the current to the motors has been may be of any desired type,imparts reciprointerrnpted. Moreover, a slow and even eating motion to along bar 2, which is pivot- 4o movement of the regulating element of theally connected with the lower ends of rockerfurnace is undesirable,because it causes the arms 3, journaled in suitable supports, as mixturein the furnace to form an arch which a. The bar 2 may extend the wholelength delays the response of the furnace regulation. of a buildingcontaining many electric fur- It is one object of the present inventionto naces 5, and it may be arranged back of and 5 45 obviate thesedefects and disadvantages and beneath the furnaces, so as to be out ofthe to provide for shifting the regulating eleway. Between the furnacesthere may be ment of the furnace with a quick jerky moprovided platforms6 for the accommodation tion, which causes the mixture to fall at onceof the attendants in charge, and at each furinto the zone or region ofreduction. nace there is a shaft 7, arranged transversely too 50 In thepresent invention use is made of of the bar 2 and provided withratchet-wheels motor apparatus which may be of any pre- 8 and 9, ofwhich the teeth are arranged in opposite directions, so that oneratchet-wheel is adapted to turn the shaft in one direction and theother is adapted to turn it in the other direction. The shafts 7 areoperatively connected with the regulating element of the furnace. Asshown, they are operatively connected with the rotatable furnace-bodies10 by means of worm -gearing. Clearly the shafts 7 can be employed, ifdesired, to shift the electrodes, and in such case the electrodes wouldbecome the regulating element of the furnace. In use the rocker-arms 3oscillate continually about their points of pivotal support, which, asshown, are in line with the shafts 7. At the upper ends of these armsare pawls 11 and 12. "When the pawl 11 is in engagement with theratchet-wheel 8, it serves to turn the shaft 7 in one direction, andwhen the pawl 12 is in engagement with the ratchetwheel 0 it operates toshift the shafts 7 in the other direction, and when both are out ofengagement the shafts 7 are not turned at all. The described movementsof the shafts 7 can be availed of to shift the regulating element of thefurnace, and thus keep the amperes in the furnace-circuit constant, aswill be hereinafter described. Moreover, the motions imparted by thepawls to the shafts 7 are somewhat jerky, and thus prevent the formationof arches in the mixture of the furnace. There is, moreover, nodeleterious result, such as would be brought about by the inertia ofmoving parts. The means whereby the power-transmission mechanism iscontrolled are hereinafter more particularly described; but I may nowcall attention to the fact that when the pawls 11 and 12 are both clearof their corresponding ratchetwheels, which is their position whenunrestrained, the movable member of the furnace may be shifted, forexample, by means of a hand-bar. For this purpose the shaft 7 is shownas provided with appropriate openings 13 for the insertion of such abar. The attendant in charge from the platform 0 may readily manipulatethe bar when necessary for this purpose. A description will now be givenof the circuits by means of which the movements of thepower-transmission devices are controlled.

let and 15 are the conductors which supply current to the electrodes.

16 is a small transformer, of which the primary is the furnace-circuititself, (amperes,) and the secondary (amperes) in the wire thatsurroundsit will be, as is well known, a small portion-say oneone-hundredth part-of the furnace-amperes. The current in the sec ondarycircuit, through suitable instrumentalities to be presently described,magnetizes and demagnetizes one or the other ofthe pawls 11 and 12, andthus serves to control the movement of the regulating member. In thisconnection itmay be stated that the pawls 11 and 12 are each providedwith diamagnetic eounterweights, as shown. "he

current from the transformer 16 operates a solenoid 17, so that when theamperage in the furnace-circuit is high the solenoid lifts its iron core18, which likewise fails when the furnace-amperage is low. Attached tothe iron core 18 is an insulated centrally-pivoted beam 10, carryingonits arms contact-bridges, substantially as illustrated. lVhen the ironcore 18 is drawn into the solenoid, it will cause one of these bridgesto enter mercurycups 20 and 21, by which a circuit is closed that causesone of the pawls of the powertransmission mechanism to engage itscorresponding ratchet-wheel, and thus rotate the furnace so as to causethe amperes in it to be reduced. Should the current in the furnace betoo low, the core 18 will fall, as shown in the drawings, closing acircuit by way of the cups 22 and 23, which causes the other pawl tocome into action, and thus to turn the furnace in the oppositedirection, which causes the current in the furnace to increase. In closeproximity to the various furnaces are placed manual switches 2-f, whichare accessible to the attendant in charge from the platform (3. Eachswitch gives control of the power-transmission mechanism from a pointnear the furnace to which it appertains. The solenoids and mercury-cups,of which there is a set for each furnace, may be located at a distancefrom the furnaces and in a position free from dust and dirt. Toillustrate this, they are shown in a separate room or building onFig. 1. The type of switch illustrated more particularly in Fig. 2 isknown in the art as a three-pole double-throw switch. In the positionshown the automatic mechanism will operate the power-transmissionmechanism; but if it is desired to stop the furnace the switch is thrownin the opposite position. This causes the power-transmission mechanismto turn the furnace the other way, and it also short-circuits thesolenoid 17, so that it has no power to lift the beam 19 out of themercury-cups 22 and In order to effect this, the poles on the three-poleswitch are reversed, as shown and as hereinafter described. The motorapparatus will continue to turn the furnace until the attendant pullsthe three-pole switch out of its contacts that is to say, into a planeat right angles with the plane of the paper of the drawings. To startthe furnace again, the attendant has only to insert the switch into itspoles in the position shown in the drawings. For the sake of a furtherdescription circuits will now be traced, and in this connection it maybe stated that the circuit 11 15 of the electrodes is assumed to bederived from some appropriate source and that 25 represents means bywhich current may be supplied for the purpose of magnetizing anddemagnetizing the pawls 11 and 12 in order to change the direction ofmotion of the regulating member of the furnace. When the furnace isoperating under automatic control, the switch 24 occupies the positionshown. Under these circumstances there is a circuit from the ICCtransformer 16 by conductors 26 and 27 to the solenoid 17, by conductor28 to common return-conductor 29, and by conductor 30 back to thetransformer 16. From the source of current 25 there is a circuit whichmagnetizes, and consequently puts into action, one or the other of thepawls 11 and 12 to shift the regulating member of the furnace in onedirection or the other, according to the position of the beam 19. Whenthe latter is in the position shown in Fig. 2, this circuit is by way ofthe conductor 32 to cup 22, bybridgepiece to cup 23, by conductor 33 tothe central arm of the switch 24, through the same by conductor 34,through the coil 35 to the conductor 36, and thence to the commonreturn. The passage of the current through the coil 35 magnetizes thepawl 11, thereby causing it to engage its ratchet-wheel 8 and to thusshift the regulating'element of the furnace in the appropriate directionfor effecting the requisite change in the amperes of the furnacecircuit.When the beam 19 has been shifted into its other position, there is acircuit from the source of current 25 by way of the conductor 37 to thecup 20, by way of the bridgepiece to the cup 21, by conductor 38 to theleft-hand arm of the switch 24, by Way of the conductor 39 to the coil40, through the same, and thence by the conductor 36 to the commonreturn. Current traversing the coil 40 magnetizes the pawl 12, wherebyitis attracted into engagement with its ratchet-wheel 9, and thus servesto rotate the furnace in the opposite direction. When the hand-switch 2ais turned down through one hundred and eighty degrees, the first steptoward stopping the furnace has been taken, and. the circuits underthese circumstances Will be traced. The circuit of the transformer 16 isshortcircuited through the conductor 26, the righthand arm of theswitch, the conductor 41,and the upper portion of the conductor 30. Theresult of this is that the weight of the core 17 shifts the lever 19into the position shown in the drawings. At the same time the conductor33 is connected byway of the center pole of the switch, so as toenergize the coil 40, with the result that the pawl 12 turns thereceptacle 5 in a counter-clockwise direction, thus uncovering theelectrodes by drawing the product away from them. As soon as this hasbeen accomplished the switch may be thrown into its third position,which is at substantially ninety degrees to the plane of the paper. Theresult of this is the reestablishment of the circuit 26 27 28 29, sothat the core 18 is drawn into the solenoid, thus dc pressing theright-hand portion of the lever 19. In this position of the switch 24the circuits that control the pawls 11 and 12 are broken at the switch,and they therefore, under the influence of their counterweights, areheld clear of the ratchet-wheels, and the f urnace remains at rest.Since the right-hand arm of the switch is depressed, it follows that assoon as the circuit is completed at the switch 24: by turning it intothe position shown in the drawings the circuit will be completed fromthe source 25 by 37, by cup 20, by bridge-piece to cup 21, by 38 toleft-hand arm of switch, by conductor 30, coil 40, conductor 36, andconductors 29 and 31 back to the source 35. Thus the pawl 12 is broughtinto action, and the furnace will commence to run in aconnter-clockwisedirection,which is desirable in starting, and will continue to run inthat direction until the core 18 is shifted in the manner described andby reason of changes in the furnace-circuit. To start the furnace again,the switch 24 is again thrown into the position shown in the drawings,and the circuits above described are again completed, so as toreestablish the automatic control of the furnace.

The core 18 of the solenoid 1'7 and also the pivotal lever 19 respond toevery change in the amperage of the furnace-circuit, even to changeswhich are permissible and incident to the process, whereas the localcircuit, controlled by the contact-bridges and mercurycups, is only madeand broken when the variations in the furnace-circuit exceedpredetermined limits depending upon the relation of the mercury-cups tothe contact-bridges. The result of this is that the movable element isshifted only in response to and so as to correct material variations inthe furnacecircuit. The use of this apparatus also permits of thelocation of the solenoid and mercury-cups remote from the dust of thefurnace, and it also insures positive engagement of the pawls 11 and 12.

It will be obvious to those skilled in the art to which my inventionappertains that modifications may be made in details Without departingfrom the spirit thereof. Hence I do not limit myself to the preciseconstruction and arrangement of parts herein set forth, and shown in thedrawings; but,

Having thus described the nature and objects of my invention, what Iclaim as new, and desire to secure by Letters Patent, is

1. Means for regulating an electric furnace having a movable element anda motor for working it which means comprise regulating relay apparatusresponding to the furnace circuit, and devices Worked by the relay forimparting motion from the motor to the movable element, said devicesarranged to respond only to predetermined variations in thefurnace-circuit thereby keeping the furnace-current approximatelyconstant.

2. Means for regulating one or more electric furnaces which comprisemotor apparatus, furnaces and their movable elements, power-transmissionmechanism for independ ently connecting the movable element of eachfurnace with the motor apparatus toshift it in either direction and fordisconnecting the same, electromechanical controlling devices inoperative position to the furnace-circuits and adapted to automaticallyactuate the power-transmission mechanism to keep the amperes constant inthe furnaces, and switches constructed and arranged to control the powertransmission byhand, to shift the regulating elements in eitherdirection, and to permit and prevent control by the clec tromechanicaldevices, substantially as described.

3. In combination an electric furnace and its movable element, apositively-driven reciprocating rocker-arm provided with two pawls,ratchetwheels connected with the movable element of the furnace andwhereof one is driven in one direction by one pawl and the other isdriven in the opposite direc tion by the other pawl, two coilsrespectively adapted to magnetize one of the pawls, andelectromechanical devices responding to the furnace-circuit and adaptedto pass currentthrough one or the other of said coils, substantially asdescribed.

4:. In combination a furnace and its movable member, ratchet-wheels forshifting the movable member in one direction or the other, pawlsnormally outof range of said ratchetwheels, means controlled by thecurrent through the furnace for shifting said pawls semen into operativeposition, and a shaft interposed between the ratchet-wheels and themovable member of thefurnace and provided. with radial openings for thereception of a hand-bar, substantially as described.

5. In combination a series of furnaces hav ing each a movable member, areciprocating bar and means for reciprocating it, rockerarms actuated bysaid bar, pawl-and-ratchet connections interposed between each rockerarmand each furnace of a series and operatively connected with the movablemember of each furnace, an electromagnet in operative position to eachfurnace-circuit, a switch controlled by each electromagnet, and a localcircuit controlled by each switch and containing electromagnetic devicesfor throwing the pawls into and out of action substantially asdescribed.

In testimony whereof I have hereunto signed my name.

\VILLIAM SMITII IIORRY.

In presence ot' DORA. s'rnnnnnncmz, W. J. JACKSON.

